"You don't have to be an expert in animal behaviour to understand it as there is no ambiguity."

The findings followed 18 months of research at the US energy department's Los Alamos facility, the country's leading nuclear weapons laboratory.

"We are very excited at the success of our research as it could have far-reaching implications for both defence and homeland security," Haarmann said.

He said the bees could be carried in hand-held detectors the size of a shoe box, and could be used to sniff out explosives in airports, roadside security checks, or even placed in robot bomb disposal equipment.

The next step would be to manufacture the bee boxes and train security guards in their use.

"It would be great to start saving some lives with this," he said.

Previously wasps have been trained to respond to traces of explosives but Haarmann said research with bees appeared to show more promise.